1 Subjects: “...skidding operation...”

2 Subjects: “...operations strategy matrix...”

3 Subjects: “...Operator 4.0...”

4 Subjects: “...mask operation...”

5 Subjects: “...operational models...”

6 Subjects: “...operational restrictions on facilities...”

7 Subjects: “...operational restrictions on facilities...”

8 Subjects: “...operability study...”

9 Subjects: “...operational assistants...”

10 Subjects: “...repair and maintenance operations...”

11 Subjects: “...repair and maintenance operations...”